1. Field of the Invention
Embodiments of the present invention generally relate to a method and apparatus for motion detection in video with large areas of detail.
2. Description of the Related Art
Various video processing operations such as noise reduction, de-interlacing (interlaced to progressive conversion), and luma-chroma separation of composite video, may rely on the accurate detection of motion in the video signal. In general, such operations adapt the processing performed based on motion detected in the video signal such that temporal processing, also referred to as three dimensional (3D) or inter-frame processing, is favored in areas of a picture where there is no motion and spatial processing, also referred to as 2D processing or intra-frame processing, is favored in areas of a picture where motion is present. Examples of such operations are described in more detail in United States Patent Publication No. 2008/0062309, entitled “Motion Detection for Interlaced Video”, filed on Sep. 7, 2007, United States Patent Publication No. 2006/0238179, entitled “Motion Detection for a Video Display System”, filed on May 24, 2005, and United States Patent Publication No. 2006/0268178, entitled “Systems and Methods for Separating Luma and Chroma Information in a Composite Video Signal”, filed on May 24, 2005. U.S. Patent Publication No. 2008/0062309 is incorporated by reference herein in its entirety.
These motion-adaptive operations rely on motion detection to measure the amount of motion at each pixel in a picture and to provide a motion parameter for each pixel that is indicative of the amount of motion detected at that pixel. Pixel differences in adjacent fields or frames are used to derive a motion measure for a given pixel. The motion measure is then mapped to a motion parameter representative of the amount of motion indicated by the motion measure. The mapping is accomplished by applying a transfer function, also referred to as a mapping function, that smoothes the transition between temporal and spatial processing. In general, the output of the transfer function, i.e., a motion parameter, is limited to a desired range, with the lower end of the range representing little or no motion and the other end representing a high degree of motion.
Based on these motion parameters, the processing performed by the motion-adaptive operation fades between temporal processing and spatial processing. Thus, if the motion detection is not accurate, temporal processing may be applied in areas of motion or spatial processing may be applied in static areas, resulting in degradation of picture quality.